Catheters for the introduction or removal of fluids may be located in various venous locations and cavities throughout the body of a patient for introduction of fluids to the body or removal of fluids from the body. Such catheterization may be performed by using a single catheter having multiple lumens. A typical example of a multiple lumen catheter is a dual lumen catheter in which one lumen introduces fluid and the other lumen removes fluid. An example of such a multiple lumen catheter is the SPLIT CATH® catheter, sold by Medical Components, Inc. of Harleysville, Pa. Catheterization may also be performed by using a multiple lumen assembly consisting of separate, single lumen catheters inserted through one or two different incisions into an area to be catheterized. An example of such a multiple lumen assembly is the TESIO® catheter, also sold by Medical Components, Inc.
Generally, to insert any catheter into a blood vessel, the vessel is identified by aspiration with a long hollow needle in accordance with the well known Seldinger technique. When blood enters a syringe attached to the needle, indicating that the vessel has been found, a thin guide wire is then introduced, typically through a syringe needle or other introducer device into the interior of the vessel. The introducer device and the guide wire are then removed, leaving the end portion of the guide wire that has been inserted into the vessel within the vessel and the opposing end of the guide wire projecting beyond the surface of the skin of the patient.
At this point, several options are available to a physician for catheter placement. The simplest is to pass a catheter into the vessel directly over the guide wire. The guide wire is then removed, leaving the catheter in position within the vessel. However, this technique is only possible in cases where the catheter is of a relatively small diameter, made of a stiff material, and not significantly larger than the guide wire. For example, this technique may be used to insert small diameter dual lumen catheters into a patient. If the catheter to be inserted is significantly larger than the guide wire, a sheath with a dilator device is passed over the guide wire to enlarge the hole. After the hole is sufficiently enlarged, the dilator and the guide wire are removed, leaving the sheath. The catheter is then inserted into the sheath. The sheath is torn and removed from around the exterior or the catheter.
However, after the dilator is removed, and before the catheter is inserted through the sheath, the sheath becomes an open conduit, allowing blood to spurt from the vessel through the sheath or allowing air to be aspirated into vessel through the sheath, such as when the patient draws a deep breath. It would be beneficial to provide a clamp that clamps off the sheath after the dilator is removed, preventing blood from spurting out the sheath or preventing air from being aspirated in prior to inserting the catheter. It would be further beneficial to provide a clamp that can be closed and opened using only one hand, so that the physician inserting the catheter still has a free hand with which to work.